The subject matter of the invention relates to an ejector or push device for pushing tubes or packages onto a mandrel.
Fibers, in particular synthetic fibers, are wound by means of so-called takeup apparatus. To this end, a takeup apparatus comprises at least one winding mandrel that holds at least one tube, on which the fiber is wound. After completing the winding operation, the package is transferred from the mandrel to a package transportation device. Such package transportation devices are also described doffers. The package transportation device is adapted for traveling along the front of the takeup apparatus. At a height, in which the winding mandrel with a fully wound package thereon is located, the package transportation device is provided with a receiving mandrel which is aligned in this position with the winding mandrel. The full package on the winding mandrel is pushed by means of a push device from the winding mandrel to the receiving mandrel of the package transportation device. It is possible to wind on one mandrel of a takeup apparatus a plurality of packages at the same time. During the transfer operation, all packages on the winding mandrel are pushed by means of the push device onto the receiving mandrel of the package transportation device. For pushing the full packages from a winding mandrel of a takeup apparatus, the push device is provided with a push unit which is displaceable substantially parallel to the winding mandrel. On the front surface of the takeup apparatus facing the machine, the push device engages from behind the winding tube, on which a fiber is wound and a package is formed, and pushes same from the winding mandrel onto the receiving mandrel. In like manner, it is also possible to push empty tubes onto the winding mandrel. Such a push device for takeup apparatus is known, for example, from EP 0 374 536 B1 and corresponding U.S. Pat. No. 5,029,762; and DE 24 38 363 C2 and corresponding U.S. Pat. No. 3,974,973.
To actuate the push unit, the push device comprises a cylinder-piston unit. The piston of the cylinder-piston unit is coupled with the push unit. The movement of the piston is transferred to the push unit. In the known push unit, the piston is connected via a piston rod to the push unit. A corresponding application of a pressure medium to the cylinder-piston unit facilitates movement of the push unit. The displacement of the push unit corresponds at least to the length of the winding mandrel, so as to make sure that the package on a winding mandrel is safely and reliably pushed onto the receiving mandrel of a package transportation device. Therefore, in the known push devices, the length of the cylinder, in which the piston is displaced, corresponds substantially to the length of the winding mandrel. In view of the fact that the push unit is displaced substantially parallel to the winding mandrel, the push unit contributes quite significantly to the length of the takeup apparatus. This necessitates a corresponding space requirement for the takeup apparatus.
Based on the foregoing, it is the object of the present invention to further develop the known push device such that same is of a compact, space-saving construction. A further object of the invention is to describe a takeup apparatus with a push device, with the takeup apparatus being of a compact construction.